Towards More Reliable Trial Court Decisions On Claim Construction

By Stephen B. Schott

The Federal Circuit, which has exclusive domain over patent-related appeals, overrules district court findings at an alarming rate. The Supreme Court has decided that turnabout is fair play. Continuing a string of reversals or at least in this case remands, the Supreme Court recently overturned years of Federal Circuit precedent and outlined a new standard of review for claim interpretation in patent litigation.
Teva v. Sandoz focused on the question of an active pharmaceutical ingredient claimed as having “a molecular weight of 5 to 9 kilodaltons.” This may seem definite but the district court thought otherwise, noting that there are 3 methods of calculating molecular weight: the weight of the most prevalent molecule, the weight of the average of all molecules, or a weighted average where heavier molecules contribute more to the calculation.
The trial court heard expert testimony on which of these definitions would be proper, found that there was no conclusive definition, and thus concluded that the claims were invalid because they were indefinite. The patent owner (Teva) appealed that holding to the Federal Circuit.
The Federal Circuit has different “standards of review” depending on what it is reviewing. Before the Teva case, when the Federal Circuit interpreted claims, it followed a de novo “from the beginning” review standard, meaning that it interpreted the claims anew, giving little deference to all the work the trial court did in interpreting the claims.
Ignoring a trial court’s analysis has been a controversial topic because trial court judges spend a lot of time getting to know the parties, their experts, inventors, and the facts surrounding the case during the trial process. The de novo standard, however, the Federal Circuit disregards much of that work and looks at just the paper record to interpret the claims.
In Teva, the Supreme Court abandons the de novo standard of review of a trial court’s claim interpretation, in part. The “in part” is a fine blade the Supreme Court draws through claim interpretation. One of the district court judge’s jobs is to determine the facts, and claim interpretation involves a mixed effort of interpreting facts (for example, expert and inventor testimony) and law (the words of the claims themselves, the patent specification) to arrive at a claim interpretation.
The Supreme Court says that the Federal Circuit can no longer review matters of fact in claim interpretation de novo, but instead must review them for “clear error,” which means that a district court judge’s reliance on facts like expert testimony will be no longer ignored; instead, a judge’s reliance on facts will be given substantial deference.
This is a boon for experts, no doubt. It should also make District Court decisions on claim interpretation less prone to being overturned. Since many claim interpretation decisions are case dispositive, and the claim interpretation decisions happen before expensive patent trials, this may reduce the total costs for patent litigation in the future.

In a lengthy dissent, Justice Thomas, joined by Justice Alito, argues that claim construction is a mixed question of fact and law that should be decided as a matter of law under the de novo standard.
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